An ultra-low noise cryogenic Ka-Band InGaAs/InAlAs/InP HEMT front-end receiver

We present here the design and performance of a 4-stage Ka-band cryogenic amplifier using a front-end 0.1-μm gate length InP HEMT. The amplifier demonstrated 20-25 K uncorrected noise temperature (/spl sim/0.3-dB noise figure) from 31-33 GHz with 30-33 dB associated gain at 12 K ambient temperature. To date, this is the best reported HEMT cryogenic amplifier performance at this frequency band and is a factor of two improvement in noise temperature compared to previous designs.